Leaving fundamentalist dogma behind, a new species of anti- evolutionists has arisen under the banner of "intelligent design" -- now at the heart of a bitter debate erupting in Ohio about how science and evolution should be taught in the public schools.

Intelligent-design advocates delve into the minutiae of biology in search of evidence that random mutation and natural selection are not enough to explain the wonders and diverse forms of nature.

The result has been a spate of books and academic papers trying to poke holes in Darwinian theories of evolution, often with elaborately detailed examples of what some call "irreducible complexity" -- the defensive apparatus of the bombardier beetle, the fine bony structures of the mammalian inner ear, the ion channels and pumps that underlie vision, the hairlike filaments that allow bacteria to swim about, the exquisite biochemical cascade that causes blood to clot the instant an injury occurs.

All are said to be examples of a designer's handiwork. The question of just who -- or what -- that designer might be is usually left open, in part to avoid charges that intelligent design is little more than a stalking horse to sneak God back into the public schools.

"It could be space aliens," said William Dembski, a mathematician and philosopher at Baylor University in Texas and author of "No Free Lunch," a new book on intelligent design. "There are many possibilities."

FUNDAMENTAL PROBLEMS

He described his main focus as a matter of elucidating some "fundamental problems with Darwinism," including what he considers some big gaps in the overwhelming scientific consensus supporting the evolutionary model.

Like most of the others in the design camp, he steers clear of the so- called "young-Earth" creationists who argue for a literal interpretation of the Book of Genesis. Instead, he talks of the complexity found in nature, perhaps evidence for "systems that have no function until you have a whole integrated package in place."

It takes a leap of faith to conclude that this means someone or something must have designed such a system. The Darwinist explanation, accepted by the overwhelming majority of biologists, holds that no such leap is necessary -- all it takes, instead, is enough time, random mutations, and a process of natural selection to propagate the accidents that confer a survival advantage.

It's a heady discussion that in some ways can be traced back to Aristotle's musings on acorns and oak trees, updated these days by a constant stream of academic cross talk on the Internet and at science-and-religion conferences.

Lately, it's jumped from esoteric journals and books to the public stage, too, after Ohio's 19-member state school board began revising science teaching standards.

PROPOSAL IN OHIO

Some Ohio school officials have proposed downgrading Darwinian evolution to allow -- or perhaps even require -- teachers to present intelligent design on more or less equal footing. Legislation has been introduced that would put more of the decision-making power in the hands of elected lawmakers. With passions rising, a school board hearing in Columbus last week attracted national attention and an audience of 1,500.

Beyond the inevitable mudslinging, Darwin's new critics insist they are engaged in essentially scientific research, parting company with the mainstream only in that they are willing to question some bedrock notions of modern biology.

"I'm not an enemy of science," said Jonathan Wells, an embryologist and senior fellow at the Discovery Institute, a Seattle think tank and the undisputed intellectual center for the intelligent-design philosophy. "I am a scientist."

"But I want science to be an open-ended search for the truth and not a dogmatic commitment to natural explanations. . . . When I look at the evidence for evolution, I see very serious problems with it."

Not surprisingly, mainstream scientists and educators tend to dismiss much of the intelligent-design movement as a pseudoscientific -- and dangerous -- masquerade.

The Discovery Institute includes several subsidiaries, with the intelligent- design component set up under something called the "Center for the Renewal of Science and Culture."

Eugenie Scott, who champions the teaching of evolution as executive director of the National Center for Science Education in Oakland, said the Seattle center's ambitious-sounding name reveals the true agenda behind the Ohio controversy.

"The cultural renewal part is really what motivates this whole effort," she said. "These are people who are very concerned about the amount of secularism in American culture. They are theists. They believe America is too secular and believe we need to bring Christian theism back into American life."

POSSIBILITY OF SPACE ALIENS

She dismisses the talk allowing for the possibility of space aliens as an agnostic patina covering an inherently religious intent.

"I wish these guys would just get real here," she said. "Everybody knows they're talking about God."

Those are fighting words among such leading intellectuals as Michael Behe, a biochemistry professor at Lehigh University and author of "Darwin's Black Box," one of the founding tomes of the intelligent-design movement.

Behe coined the term "irreducible complexity," the idea that some natural structures, like mousetraps, consist of many parts functioning as an interlocking system.

It's difficult to imagine how such systems might have evolved, although that is exactly what many biologists spend their careers doing. But for Behe and his allies, it's illogical that biological mousetraps could have gradually formed from Darwinian "gradualistic evolution."

Behe's favorite example is the flagellum, a whiplike structure that serves as a kind of rotary propeller for certain cells, bacteria and protozoans.

Although its function seems simple enough, a close look at the structural and biochemical details shows there's nothing simple about it. Where Behe parts company with most of his scientific colleagues is his claim that the individual components of the propeller make no biological sense except as elements of the completed molecular machine.

NO FOREBEARS

There seem to be no obvious evolutionary forebears in nature, and certainly no fossil record, to explain how such a machine might have been selected for through a series of random mutations in some simpler flagellum-like structures.

"If you don't have intermediate structures, it could mean one of two things, " Behe said. "Either we just haven't found them, or they are not there. It's a good bet, with these biochemical machines, that they aren't there."

Others suggest the flagellum came about from cell structures that developed for other reasons. But Behe concludes that it more logically happened as the result of a plan -- stuck onto the skin of some primordial bacterium by some clever designer.

"We are arriving at this conclusion based strictly on the physical evidence,

the structure of these physical systems," Behe said. "We're not quoting from the Bible."

He, too, was a bit cagey as to who might have done the designing.

"Certainly, many people think the designer is God," he said, allowing that as a Roman Catholic himself, "it seems natural to think that. . . . But I hasten to add that the identity of the designer is not inscribed in the cell."

Scott, at the National Center for Science Education, makes no argument on that point. But she does insist that most of the other intelligent-design arguments are wrong. "They want to change the ground rules under which we do science for the last 200 years," Scott said.

And even if there is an element inspiring healthy debate among professional scientists, she and most other mainstream experts suggest it's clearly not the sort of thing that's appropriately taught to students in publicly financed classrooms.

One of the basic ground rules of science, Scott said, is to cede the realm of the supernatural to theologians, focusing instead on finding natural explanations for natural phenomena, no matter how complex they seem to be.